It’s popular today for people and companies to try to offset their carbon footprint. But there’s a lot of debate about just how to measure that footprint. Now a new program called Carbon Hero may have one solution. The device was invented by a graduate student at the Royal College of Art in London and recently won the 2007 European Satellite Navigation Competition. The idea is to get an accurate read on how much carbon you use as you travel. It’s a hand-held unit, about the size of a key chain. It automatically identifies the form of transportation the carrier is taking by measuring the speed, location, and pattern of the movement. Then the information is automatically downloaded to a cellphone, which immediately displays the carbon generated and the impact of the user’s actions.

Of course, the device doesn't measure other aspects of a carbon footprint, such as the size of your house. And it’s not yet available to consumers. But the inventor hopes to develop the device, and that the immediate feedback will convince people to change their transportation. Maybe to walking. Which leaves a tiny footprint.

—Cynthia Graber

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